This invention relates to a filter for fluids which has a substantially pot-like housing which comprises a mounting flange and a cover, and a filter insert disposed in the housing, which comprises a pleated filter element with end plates. As used herein the term "pot-like" refers to a cylindrical shape with at least one open axial end.
U.S. Pat. No. 5,538,626 (=EP 692,292) discloses a fluid filter, especially for oil or fuel in an internal combustion engine. This fluid filter consists of a filter housing with at least one fluid inlet and one fluid return passage, and a removable cover closing the filter housing in a leak-proof manner. A single replaceable filter insert is disposed in the filter housing. The fluid filter is affixed to a supporting structure by a hollow fastening screw forming a fluid passageway.
A disadvantage of this state of the art is to be seen in the fact that, in a fluid filter subjected to great pressure fluctuations, considerable sealing problems arise since it is mounted by a central screw. In a replaceable filter element which is regularly replaced and in which the gasket is also regularly renewed, such a danger would not exist to this extent in a filter which would assure over a long period of time a reliable seal with this kind of screw mounting.
U.S. Pat. No. 5,042,999 (=DE 3,918,347) discloses an air intake filter for internal combustion engines, which has a pot-like housing in which a filter insert is disposed. The mounting of the housing on a part of the engine is achieved by a track with a sliding block and supporting surfaces as well as snap catches. This construction, however, is unsuited to fluid filters since, as already mentioned, pressure fluctuations and elevated internal pressures can occur. An effective seal cannot be achieved with this type of mounting.